<!DOCTYPE html>
<html lang="zh-CN">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        ul {
            list-style: none;
        }

        .box {
            margin: 20px auto;
            width: 300px;
            padding: 20px;
            border: 2px solid lightblue;
        }

        .box li:nth-child(2n) {
            background-color: pink;
        }

        .box li {
            line-height: 35px;
            border-bottom: 1px dashed orange;
        }

        .box li:last-child {
            border-bottom: none;
        }

        .box li:hover {
            background-color: brown;
        }
    </style>
</head>

<body>
    <ul class="box">
        <li>我是第一个</li>
        <li>我是第二个</li>
        <li>我是第三个</li>
        <li>我是第四个</li>
        <li>我是第五个</li>
    </ul>
</body>

</html>